1. Field of the Invention
This invention relates to linear copolymers of vinyl pyrrolidone and long chain alpha-olefins and, more particularly, to such copolymers in the form of flakes or powders.
2. Description of the Prior Art
U.S. Pat. Nos. 3,406,238; 3,417,054; 3,309,365; 3,423,381; and 3,423,367 describe the preparation of alkylated polymers of heterocyclic N-vinyl monomers by the simultaneous polymerization and alkylation of heterocyclic N-vinyl monomers and long chain alpha-olefin comonomers. Alkylated vinyl pyrrolidone copolymers, for example, are known as Ganex.RTM. polymers, and are sold by International Specialty Products. Typically, Ganex.RTM. V-216 is sold in the form of a straw-colored viscous liquid while Ganex.RTM. V-220 is a waxy solid. Other Ganex.RTM. polymers having different long chain alkyl groups therein are known but these are also prepared as bulk solids.
The use of Ganex.RTM. copolymers as a waterproofing agent in sunscreen products is well known. However, its main disadvantage of bulk solids is that it is inconvenient to process into such formulations.
Accordingly, it is desired to provide such copolymers as flakes or powders which could be handled more easily, and, perhaps, have superior waterproofing properties in a personal care composition, such as a sunscreen composition than the bulk form.
Another sought-after objective of this invention is to provide a process for making copolymers of vinyl pyrrolidone and long chain alpha-olefins in the physical form of flakes or powders.
These and other objects and features of the invention will be made apparent from the following description of the invention.